Methanosarcina acetivorans
| Methanosarcina acetivorans C2A | |
|---|---|
| Scientific classification | |
| Domain: | Archaea |
| Kingdom: | Euryarchaeota |
| Phylum: | Euryarchaeota |
| Class: | Methanomicrobia |
| Order: | Methanosarcinales |
| Family: | Methanosarcinaceae |
| Genus: | Methanosarcina |
| Species: | M. acetivorans |
| Binomial name | |
| Methanosarcina acetivorans Sowers et al. 1986 | |
Methanosarcina acetivorans is a versatile methane producing microbe which is found in such diverse environments as oil wells, trash dumps, deep-sea hydrothermal vents, and oxygen-depleted sediments beneath kelp beds. Only M. acetivorans and microbes in the genus Methanosarcina use all three known metabolic pathways for methanogenesis.[1] Methanosarcinides, including M. acetivorans, are also the only archaea capable of forming multicellular colonies, and even show cellular differentiation. As of 2006, the genome of M. acetivorans is the largest of all sequenced archaeal genomes.[2]
In 2006, James Ferry and Christopher House discovered that M. acetivorans uses a previously unknown metabolic pathway to metabolize carbon monoxide into methane and acetate using the well known enzymes phosphotransacetylase (PTS) and acetate kinase (ACK). This pathway is surprisingly simple, and has been proposed by Ferry and House as perhaps the first metabolic pathway used by primordial microbes.
However, in the presence of minerals containing iron sulfides, as might have been found in sediments in a primordial environment, acetate would be catalytically converted into acetate thioester, a sulfur-containing derivative. Primitive microbes could obtain biochemical energy in the form of adenosine triphosphate (ATP) by converting acetate thioester back into acetate using PTS and ACK, which would then be converted back into acetate thioester to complete the process. In such an environment, a primitive "protocell" could easily produce energy through this metabolic pathway, excreting acetate as waste. Furthermore, ACK catalyzes the synthesis of ATP directly. Other pathways generate energy from ATP only through complex multi-enzyme reactions involving protein pumps and osmotic imbalances across a membrane.
See also
- RNA world
- Origin of life
References
Further reading
- Ascenzi, Paolo; Loris Leboffe,, Loris; Pesce, Alessandra; Ciaccio,, Chiara; Sbardella, Diego; Bolognesi, Martino; Coletta, Massimo (14 May 2014). "Nitrite-Reductase and Peroxynitrite Isomerization Activities of Methanosarcina acetivorans Protoglobin". PLoS ONE (2014) 9 (5): e95391. doi:10.1371/journal.pone.0095391.
- Isobe, Keisuke; Ogawa, Takuya; Kana Hirose, Kana; Yokoi, Takeru; Yoshimura, Tohru; Hemmi, Hisashi (2014). "Geranylgeranyl Reductase and Ferredoxin from Methanosarcina acetivorans Are Required for the Synthesis of Fully Reduced Archaeal Membrane Lipid in Escherichia coli Cells". Journal of Bacteriology 196 (2): 417–423. doi:10.1128/JB.00927-13.
- Rother, Michael (November 2007). "Genetic and proteomic analyses of CO utilization by Methanosarcina acetivorans". Archives of Microbiology 188 (5): 463–472. doi:10.1007/s00203-007-0266-1.
- Suharti, Suharti; Wang, Mingyu; de Vries, Simon; Ferry, James (16 May 2014). "Characterization of the RnfB and RnfG Subunits of the Rnf Complex from the Archaeon Methanosarcina acetivorans". PLoS One 9 (5). doi:10.1371/journal.pone.0097966.
External links
- Putting Life's Puzzle Together from Astrobiology Magazine (17 May 2006)
- The Genome of M. acetivorans Reveals Extensive Metabolic and Physiological Diversity
- How Life Began: New Research Suggests Simple Approach Michael Schirber (LiveScience) 9 June 2006 09:09 am ET